xref: /src/bin/echo/echo.1 (revision 7e68976408e4df21e120e2d6440392302cac84f3)

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.Dd October 5, 2016
.Dt ECHO 1
.Os
.Sh NAME
.Nm echo
.Nd write arguments to the standard output
.Sh SYNOPSIS
.Nm
.Op Fl n
.Op Ar string ...
.Sh DESCRIPTION
The
.Nm
utility writes any specified operands, separated by single blank
.Pq Ql "\ "
characters and followed by a newline
.Pq Ql \en
character, to the standard
output.
.Pp
The following option is available:
.Bl -tag -width flag
.It Fl n
Do not print the trailing newline character.
.El
.Pp
The end-of-options marker
.Fl Fl
is not recognized and written literally.
.Pp
The newline may also be suppressed by appending
.Ql \ec
to the end of the string, as is done
by iBCS2 compatible systems.
Note that the
.Fl n
option as well as the effect of
.Ql \ec
are implementation-defined in
.St -p1003.1-2001
as amended by Cor.\& 1-2002.
For portability,
.Nm
should only be used if the first argument does not start with a hyphen
.Pq Ql "-"
and does not contain any backslashes
.Pq Ql "\e" .
If this is not sufficient,
.Xr printf 1
should be used.
.Pp
Most shells provide a builtin
.Nm
command which tends to differ from this utility
in the treatment of options and backslashes.
Consult the
.Xr builtin 1
manual page.
.Sh EXIT STATUS
.Ex -std
.Sh EXAMPLES
Special treatment of options and backslashes:
.Bd -literal -offset indent
$ /bin/echo "-hello\\tworld"
-hello\tworld
.Ed
.Pp
Avoid new line character:
.Bd -literal -offset indent
$ /bin/echo -n hello;/bin/echo world
helloworld
.Ed
.Pp
Or to achieve the same result:
.Bd -literal -offset indent
$ /bin/echo "hello\\c";/bin/echo world
helloworld
.Ed
.Sh SEE ALSO
.Xr builtin 1 ,
.Xr csh 1 ,
.Xr printf 1 ,
.Xr sh 1
.Sh STANDARDS
The
.Nm
utility conforms to
.St -p1003.1-2001
as amended by Cor.\& 1-2002.
.Sh HISTORY
The
.Nm
command appeared in
.At v2 .
.Sh CAVEATS
The
.Nm
command behaves differently with regards to the built-in
.Nm
shell command in a number of ways including escaped characters handling.
It also differs in behavior between different systems hence complicating writing
portable scripts.
It is advised to use the
.Xr printf 1
command to avoid these shortcomings.